1) make a chain in one direction and leave it to accumulate modifiers that you link to in the other three directions, then farm it when your original chain has like 10 mods each tile, so they're more proifitable

2) link to direct reward nodes like chests and such

3) link to bosses for drops.

Each tile that gets actually placed (not planned, but actually placed down) will advance the memory nexus like a "turn" in a turn based game like Civilization or something. Each of these "turns" has a chance to spawn reward tiles, memory modifier tiles, or boss tiles. There appears to be a sort of minimum number of each of these, so if you want chests, don't run memory mods or bosses... if you want bosses, don't run memory mods or chests, if you want memory mods, don't run bosses or chests.

2nd -- the number of implicits an item will get is simply tied to the number of fractured mods that go in. Put in 3 items each with 3 fractured mods, you get an item that will have 3 implicits.

Not sure what happens when you put in items with like 2 fractured mods and 1 fractured mod mixed together, but you get the idea.